Crate V5 mods... anyone?

[cebreez]

P.S. I saw jim p's original post but none pictures were there to show what he did. The guy really knows what he is doing but I had a hard time following his explanations. I wish I had been a member then and gotten into the discussion. I believe he was on the right track but I would have loved to coax him into a different direction. When I get this figured out and eventually I will, I will do my best to post the schematic markups. I totally disagree with the "sledgehammer" idea. This amp is a real sleeper and has almost everything you would find in amps costly "x infinity" more. I am thinking too about a different output transformer to boost this to a 10 or 15 watt amp but haven't gotten past the input circuit yet.

[tunghaichuan***]

P.S. I saw jim p's original post but none pictures were there to show what he did. The guy really knows what he is doing but I had a hard time following his explanations. I wish I had been a member then and gotten into the discussion. I believe he was on the right track but I would have loved to coax him into a different direction. When I get this figured out and eventually I will, I will do my best to post the schematic markups. I totally disagree with the "sledgehammer" idea. This amp is a real sleeper and has almost everything you would find in amps costly "x infinity" more. I am thinking too about a different output transformer to boost this to a 10 or 15 watt amp but haven't gotten past the input circuit yet.

You might have to replace the power transformer as well as the output transformer. Boosting the amp from 5 watts to 10-15 watts is not as easy as it might seem. There are several ways you could go about it.

You could add another EL84 in parallel to give you 10 watts, but you'd have to use an output transformer with half the primary impedance as the existing unit. You'd have to replace the power transformer with one that has double the current capacity as the stock unit.

If you wanted to move up to a larger, single power tube, you could probably get 10 watts out of a 6L6GC tube in SE. But again you'd have replace both stock transformers with appropriate new units.

For 15 watts in SE operation, you'd need to go to a 6550 or a KT88.

All of the above are for single ended operation, and the larger the tube, the heavier the transformers get to handle the increased current. These transformers also tend to be very expensive.

You could completely gut the amp and build in a push pull circuit using two EL84s or 6V6s. But then you have to add a phase inverter to operate the amp in push pull. This is in addition to the existing preamp circuit. The transformers would be smaller and lighter, but the question is: do you have enough room in the chassis for the extra circuitry?

Modding a 5W amp into a 10-15 watt amp is not an economical way to get a killer practice amp. Really, you'd be better off buying a commercial amp that already has the features you want.

[cebreez]

I totally get what your saying and all options that I have considered. Wasn't thinking about the power transformer, good point. Definitely not enough room to start adding more tube circuitry. Larger tube...? Well...? Maybe. Expense is definitely the issue. I have a larger tube amp but not really wanting to go that route. Want to keep this one small and compact. Played with my BBE Sonic Maximizer in front of the Crate today and love the tonal difference it made. Gave it clarity and very nice harmonics. Liked it so much I ordered a pcb for a look-a-like on "madbeans.com". Might try to incorporate that on the input or in place of it. Also considered a nice 4 knob preamp pedal circuit for the same reason. Would add the necessary gain and EQ on the front end while still keeping it clean and low noise.